Abstract

We describe an integrated microwaveimaging system that can provide spatial maps of dielectric properties of heterogeneous media with tomographically collected data. The hardware system was built based on a lock-in amplifier with 16 fixed antennas. The reconstruction algorithm was implemented using a Newton iterative method with combined Marquardt-Tikhonov regularizations. System performance was evaluated using heterogeneous media mimicking human breast tissue. Finite element method coupled with the Bayliss and Turkel radiation boundary conditions were applied to compute the electric field distribution in the heterogeneous media of interest. The results show that inclusions embedded in a 76-diameter background medium can be quantitatively reconstructed from both simulated and experimental data. Quantitative analysis of the microwaveimages obtained suggests that an inclusion of in diameter is the smallest object that can be fully characterized presently using experimental data, while objects as small as in diameter can be quantitatively resolved with simulated data.

Received 11 August 2004Revised 14 September 2004Accepted 14 September 2004Published online 12 November 2004

Acknowledgments:

The authors are grateful to Xing Wang for his assistance in the hardware implementation. The authors also would like to thank Professor Andre W. Peterson for stimulating discussion. This research was supported in part by the Provost’s office of Clemson University.